Screw anchor adapter



G. A. M. PETERSEN 2,883,223

SCREW ANCHOR ADAPTER April 21, 1959 2 Shets-Sheet 1 Filed July 15. 1954FIEI 3 IN V EN TOR. GERALD AM PETERSEN Ap 1, 1959 G. A. M. PETERSEN2,883,223

SCREW ANCHOR ADAPTER Filed July 15, 1954 2 Sheets-Sheet 2 INVENTOR.GERALD AM PETERSEN 24MMM United rates Patent 2,883,223 SCREW ANCHCRADAPTER Gerald A. M. Petersen, Santa Clara, Calif. Application July 15,1954, Serial No. 443,633 Claims. (Cl. 287-408) This invention relates toan adapter for drivingly connecting a screw anchor rod to the tip of anearth boring tool for driving the screw anchor into earth.

Screw anchors as such are not new, since it has long been a practice todrive these anchors by screw action into earth to provide anchorage forguy wires or cables. These screw anchors in general consist of anelongated rod having an eye formed on its upper end and its opposite endpointed and provided with a double helix blade which is relatively fiatbut will screw into earth, sand or clay in auger fashion. The generalpurpose is to screw the blade well into earth to obtain anchorage of therod therein to withstand direct pull thereagainst by guy wires connectedto the eye of the rod.

Heretofore it has been the practice to drive the screw anchor into earthby either hand operaion or by leverage, but preferably by some form ofpower drive means. Since these screw anchors are usually employed inconjunction with power poles and installed by the same crew it has beenthe custom to use the same power drive as is used for the earth boringauger by which the holes are dug for reception of the power poles. Whilethis practice is satisfactory insofar as driving the anchor rod intoearth by power means is concerned, much time and loss of man hours isincurred by reason of the fact that the earth boring auger has to beremoved from the power drive and another adapter or fitting secured tothe drive means for coupling the same to the eye of the anchor rod.

The present invention has as its object the provision of I These andother objects of the present invention will become more apparent from areading of the following description together with the drawings inwhich:

Fig. 1 is a side elevational view of a screw anchor coupled to an earthboring auger by an adapter fitting; i

embodying the present invention.

Fig. 2 is a vertical section through the adapter seen in Fig. 1.

Fig. 3 is a bottom plan view of the adapter of Fig. l. as seen from line3--3 therein.

Fig. 4 is a side view of the adapter only of Fig. 1 as: seen from line44 therein.

Fig. 5 is a top plan view of the adapter only as seen. from above inFig. 4.

Fig. 6 is a front side View of the adapter as seen in Fig. 1 but atlarger scale with respect thereto.

Fig. 7 is a horizontal section through the adapter of Fig. 4 and takenalong line 77 therein.

Referring now to Figs. 1 and 2, the screw anchor rod generallydesignated 10 is shown coupled to an earth boring auger 11 by means ofthe adapter fitting 12 of the the present invention. As shown in Fig. 1,the screw anchor has its double helix blades 13 embedded in earth E andits eye portion 14 above the surface S of the earth for connection withthe adapter fitting 12.

The earth boring auger 11 comprises a drill shaft 15 having its upperend suitably connected to a power drive means (not shown) in anyconventional manner. In this connection the drill shaft 15 is considereda power driven shaft insofar as the description of this invention isconcerned. The driven drill shaft 15 is provided with the usual helicalblades 16 which may be of the single or double helix of conventionaldesign in earth boring tools. The earth engaging end of the driven drillshaft 15 is provided with a pilot bit 17 usually consisting of a fiattriangular starting tip for entering earth and breaking the way for thelarger radial helical blades 16 of the auger.

For purposes of the present disclosure I have shown a fish-tail typepilot bit having helical blades 18 of the double helix type. Moreparticularly, the pilot bit 17 in the present disclosure has featuresand characteristics more specifically defined and claimed in mycopending application, Serial No. 414,007 filed March 4, 1954, andissued December 11, 1956, as Patent No. 2,733,673 from the United StatesPatent Office. For purposes of this disclosure sulfice it to say thatthe pilot bit 17 preferably has diammetrically extending blades topresent a tip of triangular shape, i.e., tapering toward an apex at froma base end of substantially the same diameter as the drill shaft 15. Inthe present disclosure the pilot bit 17 has a pair of diammetricallydisposed fins 1919 extending beyond its apex a in the form of what Iprefer to call a fish tail 20. It should here be understood that thehelical blades 18 of the pilot bit may be relatively fiatdiamrnetrically opposed radial blades which serve to chew into earth tobreak up the solid pack thereof.

With the foregoing in mind refer now to the screw anchor adapter 12 ofthe present invention as shown in Fig. 2 which consists of a unitarycasting 21 formed with a relatively hollow core 22 divided between itsupper and lower ends 23 and 24, respectively, by a reinforcing web orwebs 26-26'. In the preferred embodiment, the reinforcing webs 26 and 26are formed integrally with a cross brace 25 (see also Fig. 7).

The upper end 23 of the adapter 12 is formed by upper walls 2727diametrically opposite and spaced from each other (Fig. 5) to provide aspace 28 for receiving the radial blades 18 of the pilot bit 17. In thissimplified form the tip of the pilot bit is stabilized relative to thecasting 21 by engagement with the reinforcing webs 26--26 and thekey-like connection of the diametrically extending blade 18 with theslot or space 28 between the walls 27-27 affords a driving connectionbetween the pilot bit and the adapter fitting 12. More specifically andin connection with cone type pilot hits, the upper walls 27-27' areoutwardly flared as shown in Fig. 4-. Each wall 27 and 27 is providedwith a lip 29 and 29', respectively, on their trailing edges for hearingrelation with the spirally extending, blades 18 of the pilot bit 17. Inconjunction with the foregoing, each side wall 27-27 is provided with aninset or recess 30-30 in the direction of turning of the pilot bit underthe influence of the drill shaft 15. These recesses 30-30 afford passageof the downwardly extending helical margins M of the blades 18 whichdiminish in radial extension from the axis of the pilot hit. As bestillustrated in Figs. 2 and 6, cross brace 25 is of a contour to bereceived in the crotch formed between the fins 19-19 of the fish tailtip 20 of the pilot bit. In this manner the apex at of the pilot bit isdisposed on the upper ridge r of the cross brace and the fins 19--19'straddle the latter for transmitting turn.- ing movement from the pilotbit to the adapter fitting 12. From the foregoing it will be seen thatthe insertion of the pilot bit 17 into a socket 31 afforded in the upperend of the adapter fitting drivingly couples the bit and adaptertogether for rotation in unison. If desired, a bolt 32 may be insertedthrough aligned bores 33--33' in the upper flared walls 2727' andthrough a hole through the base of the pilot bit 17. The bolt 32 therebyserves to maintain the pilot bit within the socket 31 particularlyduring reverse turning of the latter and drill shaft should it bedesirable to withdraw the screw anchor from the earth E.

The opposite or lower end 24 of the unitary casting 21 is key like inthat it is a flange of relatively ovoid shape 34 having its longdimension suitable to receive the eye 14 of the anchor rod but itsnarrower dimension less than the diameter of the eye 14 for hearingrelation therewith during turning of the adapter, see Fig. 3. The upperend of the eye 14 normally bears against the reinforcing diaphragm orwebs 26-26' during axial pressure from the drill shaft 15 through theadapter 12 and against the anchor rod eye 14. In this manner, theturning of the adapter 12 by action of the pilot bit 17 and drill shaft15 is transmitted to the eye 14, anchor rod 10, and its helical blades13 to drive the latter in screw fashion into the earth E. For the samereasons as stated in connection with the pilot bit 17, a bolt 35extended through aligned openings 36-46 in the ovoid flange 34 at thelower end 24 of the casting 21 and through the eye 14 serves to maintainthese parts together.

From the foregoing it will be apparent that I have provided a simple yeteffective adapter fitting 12 for drivingly coupling a screw anchor tothe lead end or pilot bit of a conventional earth boring auger 11.Moreover, since the adapter casting 21 has a dual ended female core forthe reception of the pilot bit and anchor rod 10 at its opposite ends,it will be apparent that the anchor rod 10 is thereby maintained indriving alignment with the driven drill shaft. It should be notedfurther that the gradually diminishing triangular or conical pilot bithas a tendency to seek bottomed relation in the socket 31 provided inthe adapter casting. Moreover, by reason of the recess formations 3030'in the flared walls of the upper end 23 of this casting clearance isafforded spiral blades when used. On the other hand, since the eye 14 ofthe screw rod 10 fits up into the ovoid flange 34 the latter confinesthe eye 14 even though it may be canted within the ovoid flange. Theforegoing is true although the screw anchor is to be driven into earthat an angle as illustrated in Fig. 1. That is to say, the anchor rod ismaintained insubstantial axial alignment with the driven drill shaft 15during turning of the latter and descent of the helical blades 13 intothe earth E.

While I have described my new screw anchor adapter in specific detail,it will be apparent that the same is susceptible of variations,alterations and/ or modifications without departing from the spirit ofthis invention. I therefore, desire to avail myself of all variations,alterations and/or modifications as fairly come within the purview ofthe appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. In earth boring equipment an adapter for coupling the looped eye endof a screw anchor to a cone-shaped pilot bit having a spirally extendingblade terminating in a fish-tail tip; comprising a unitary castinghaving an ovoid socket at one end for receiving the looped eye end ofsaid screw anchor, a cross brace midway the ends of said casting adaptedto bear against the looped eye end of said screw anchor and having anupwardly facing rib adapted to receive and be straddled by the fish-tailtip of said pilot bit, and a pair of side walls on said casting abovesaid cross brace spaced from each other transversely of said cross braceand configurated to receive the spirally extending blade of saidcone-shaped pilot bit for driving connection therewith.

2. In earth boring equipment an adapter for coupling the looped eye endof a screw anchor to a dual helix pilot bit; in which each helix has adownwardly spiral trend toward an apex, comprising a unitary castinghaving an ovoid socket formed in its lower end for receiving the loopedeye end of said screw anchor rod, a diaphragm between the upper andlower ends of said casting, the upper end of said casting comprising apair of side walls spaced from each other to facilitate the reception ofthe dual helix of said pilot bit therebetween, each of said side wallshaving one edge thereof disposed to bear against the leading face of onehelix of said pilot bit and recessed adjacent said diaphragm to conformto the downwardly spiral trend of the helix of said pilot bit.

3. In an earth boring auger an adapter fitting for coupling the loopedeye end of a screw anchor to a coneshaped pilot bit provided withsymmetrical spirally extending helical blades; the combination with-aunitary casting having its lower end formed to receive the looped eyeend of said screw anchor, of outwardly flared opposite side walls on theupper end of said casting conforming to the cone shape of said pilot bitand spaced from each other to receive said cone-shaped pilot bit, saidopposite side walls each having a lip spaced from the adjacent edge ofthe other side wall and configurated to rest against the leading face ofa respective one of said spirally extending helical blades of said pilotbit for driving connection therewith.

4. ,In an earth boring auger an adapter fitting for coupling the loopedeye end of a screw anchor to a pilot bit provided with spirallyextending radial blades terminating in a fish-tail tip; the combinationwith a unitary casting having an ovoid socket formed in its lower end toreceive the looped eye end of said screw anchor in key-like fashion, ofa cross brace midway the upper and lower ends of said casting forhearing relation with the looped eye end of said screw anchor andadapted to be straddled by the fish-tail tip of said pilot bit, a pairof side walls on the upper end of said casting spaced from each otherfor receiving the spirally extending radial blades of said pilot bitbetween them, each said side wall having a recess formed on its trailingedge conforming in contour to the leading faces of said spirallyextending blades for driving engagement therewith during turning of saidpilot bit with said auger.

5. In an auger an adapter fitting for coupling the looped eye end of ascrew anchor to a cone-shaped pilot bit provided with spirally extendinghelical blades terminating in a fish-tail tip; the'combination with aunitary casting having its lower end formed to provide an ovoid socketfor receiving the looped eye end of said screw anchor in key-likefashion, of an integral cross brace midway the ends of said castingadapted to be straddled by the fishtailed tip of said pilot bit, theupper end of said casting having outwardly flared opposite side wallsfor receiving said cone-shaped pilot bitbetween them, and the trailingedge of each of said side walls conforming to the downward spiral trendof said spirally extending helical blades for bearing relation therewithupon turning of said pilot bit.

References Cited in the file of this patent UNITED STATES PATENTS200,203 Knox Feb. 12, 1878 1,114,723 Berry Oct. 27, 1914 1,158,895 ClarkNov. 2, 1915 1,349,428 Marshall, Ir. Oct. 10, 1920 1,532,662 Risser Apr.7,1925 1,824,892 Hoke a- Sept. 29, 1931 2,099,921 Becker Nov. 23, 19372,248,733 Anderson July 8, 1941 2,569,528 Kandle Oct. 2, 1951 FOREIGNPATENTS 10,743 Great Britain 1913 137,771 Sweden Oct. 28, 1952

